I worked with a company where there were 2 founders and one of them told the other guy he would like to retire so he got bought out. He was still working for the company while the other guy went on vacation. 2 weeks later he came back, not a single one of all the orders was finished and he had introduced his new company to all customers.

In the months leading up to all this, the "evil" partner had bought an exact copy of all the machinery and software.

It was illegal what that guy had done and he was at risk of doing some time in jail. They eventually settled for a price that was way too low because the victim was tired of it, he couldn't stop thinking about it, he couldn't sleep, he wanted it to stop.

Here's the kicker. The evil partner had done it 2 times before and his latest victim knew about it when they founded the company, but figured it wouldn't happen again because the evil guy was close to retirement.

Lesson learned ? I don't know. Trust your gut ?